It will invokes the Apex classes to run at specific time.
Anybody who want to schedule their class they have to implement schedulable interface.
Schedule Interface: The class that implements this interface can be scheduled to run at different intervals. This interface has several methods they are
Public void execute(schedulablecontext sc)
Public class mySchedule implements schedulable
{
Public void execute(schedulablecontext sc)
{
Account a = new Account(Name = ‘Faraz’)
Insert a;
}
}